On the coupling between Tropical Upper Stratospheric Winds and the Polar Vortex
The wintertime circulation of the extratropical stratosphere is characterized by a strong band of circumpolar eastward winds called the polar vortex. Several external factors, including tropical stratospheric Quasi Biennial Oscillation (QBO), El-Nino Southern Oscillation (ENSO), Madden-Julian Oscill...
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ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_5021757 2023-07-30T04:01:48+02:00 On the coupling between Tropical Upper Stratospheric Winds and the Polar Vortex Neelakantan, K. Kumar, K. 2023-07-11 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5021757 eng eng info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-4323 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5021757 XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) info:eu-repo/semantics/conferenceObject 2023 ftgfzpotsdam https://doi.org/10.57757/IUGG23-4323 2023-07-16T23:40:25Z The wintertime circulation of the extratropical stratosphere is characterized by a strong band of circumpolar eastward winds called the polar vortex. Several external factors, including tropical stratospheric Quasi Biennial Oscillation (QBO), El-Nino Southern Oscillation (ENSO), Madden-Julian Oscillation (MJO), the 11-year solar cycle, and arctic snow have been found to influence the polar vortex. Recent studies have revealed that the tropical upper stratospheric winds also have a robust influence on the polar vortex. In this study, we use reanalysis datasets to study the coupling between the northern hemispheric polar vortex and the tropical upper stratosphere where the Semiannual Oscillation (SAO) is dominant. We identify a remarkable association between the temporal evolution of the polar vortex and SAO zonal winds. The results are contrasted for winters with and without major Sudden Stratospheric Warming (SSW) events. Eliassen-Palm flux diagnostics are used to explain the physical mechanism underlying this connection. Finally, long-term trends in the strength of the SAO zonal winds are presented, and potential implications for polar vortex dynamics are discussed. Conference Object Arctic GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) Arctic |
institution |
Open Polar |
collection |
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) |
op_collection_id |
ftgfzpotsdam |
language |
English |
description |
The wintertime circulation of the extratropical stratosphere is characterized by a strong band of circumpolar eastward winds called the polar vortex. Several external factors, including tropical stratospheric Quasi Biennial Oscillation (QBO), El-Nino Southern Oscillation (ENSO), Madden-Julian Oscillation (MJO), the 11-year solar cycle, and arctic snow have been found to influence the polar vortex. Recent studies have revealed that the tropical upper stratospheric winds also have a robust influence on the polar vortex. In this study, we use reanalysis datasets to study the coupling between the northern hemispheric polar vortex and the tropical upper stratosphere where the Semiannual Oscillation (SAO) is dominant. We identify a remarkable association between the temporal evolution of the polar vortex and SAO zonal winds. The results are contrasted for winters with and without major Sudden Stratospheric Warming (SSW) events. Eliassen-Palm flux diagnostics are used to explain the physical mechanism underlying this connection. Finally, long-term trends in the strength of the SAO zonal winds are presented, and potential implications for polar vortex dynamics are discussed. |
format |
Conference Object |
author |
Neelakantan, K. Kumar, K. |
spellingShingle |
Neelakantan, K. Kumar, K. On the coupling between Tropical Upper Stratospheric Winds and the Polar Vortex |
author_facet |
Neelakantan, K. Kumar, K. |
author_sort |
Neelakantan, K. |
title |
On the coupling between Tropical Upper Stratospheric Winds and the Polar Vortex |
title_short |
On the coupling between Tropical Upper Stratospheric Winds and the Polar Vortex |
title_full |
On the coupling between Tropical Upper Stratospheric Winds and the Polar Vortex |
title_fullStr |
On the coupling between Tropical Upper Stratospheric Winds and the Polar Vortex |
title_full_unstemmed |
On the coupling between Tropical Upper Stratospheric Winds and the Polar Vortex |
title_sort |
on the coupling between tropical upper stratospheric winds and the polar vortex |
publishDate |
2023 |
url |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_5021757 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-4323 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5021757 |
op_doi |
https://doi.org/10.57757/IUGG23-4323 |
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1772812545088815104 |